Steam jet refrigeration apparatus



2 Sheets-Sheet l E. F. sTALcUP Filed April 24, 1956 HIGH PREssuR EJEcToRATTORNEY STEAM JET REFRIGERATION APPARATUS Jan. 25, 1938.

Jan. 25, 1938. E. F. sTALcuP STEAM JET REFRIGERATION vAPPARATUS FiledApril 24', 1956 2 SheetS-Sheet 2 wlTN EssEs INVENTOR EnNcs-r F'.STALcuP.

BY QJIRIRW ATTORNEY Patented Jan. 25, 1938 UNITED STATUE STEAM .ETBEFRIGERA'IION PPARA'US Ernest F. Stalcup, Rutledge, Pa., assigner toWestinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., acorporation of Pennsylvania Application April 24, 1936, Serial No.76,228

6 Claims.

My invention relates to vapor jet refrigerating apparatus, moreparticularly to an installation in which a supply of low pressure steamis available and in which a source of high pressure steam is providedfor supplementing the low pressure supply, and it has flor an object toprovide improved apparatus.

A particular object is to provide apparatus of improved economy ofoperation.

In accordance with my invention, Iprovide an evaporator, one or moreejectors using steam-of` relatively low pressure, one or more ejectorsusing steam of relatively high pressure, and means for condensing thevapor exhausted from the ejectors. The latter is divided into aplurality of condensing chambers through which cooling water iscirculated in series, a higher vacuum being thereby eiected in theflrstcondensing chamber. The low pressure ejectors are arranged toexhaust into the rst condensing chamber in which the higher vacuum ismaintained, and the high pressure ejectors are arranged to exhaust intothe second condensing chamber. Thus the better vacuum is utilized toprovide most economical operation of the low pressure ejectors. This isdesirable as the low pressure steam supplied to such ejectors is usuallywaste steam, such as exhaust from auxiliaries, and it is economical touse such steam as far as possible. Also, the higher vacuum provides abetter heat drop or pressure drop for the low pressure steam.

These and other objects are eiected by my invention, as will be seenfrom the following description and claims taken in connection with theaccompanying drawings, and forming a part of this application, in which:y

Fig. 1 is an end elevation of the apparatus, partly in section, as seenalong the line I-I of Fig. 2;

Fig. 2 is a plan view thereof; and,

Fig. 3 is a diagrammatic view of a second embodiment.

Referring in detail to the embodiment shown in Figs. 1 and 2, theapparatus includes an evaporator I0 through which water or other uid tobe cooled is circulated. 'I'he evaporator may be of any suitable typeknown in the art, having either a single chamber or a plurality ofchambers through which the water may be circulated either ,in parallelor in series. In the embodiment of Figs. 1 and 2, the evaporator I0 isshown as comprising a single chamber, and it is provided with an inletconnection Il and an outlet connection `I2 for the circulation of watertherethrough.

The present invention is applicable to an installation in which there isavailable a variable or limited supply of motive uid of relatively loWpressure, for example, steam exhausted from aux'- iliaries at a pressureof 2'lbs. per square inch, which exhaust would otherwise `be wasted.There are provided two ejectors I3 which are constructed and designedfor operation with such low pressure steam, which is delivered theretothrough a main,conduit I4 and branch conduits I5, the latter havingvalves I6. The suctionl inlets of the ejectors I3 are connected to theevaporator at Il, Valves I8 being preferably interposed in suchconnections. In order to supplement the action of the low pressureejectors I3, a number of ejectorsl I9 are provided, which are designedand constructed for economical operationwith motive fluid of higherpressure from a suitable available source. The high pressure motivefluid, usually steam, is conveyed through a main conduit 2| and branchconduits 22 having valves 23. The suction inlets 24, of the ejectors I9are connected to the evaporator; preferably through valves 25.

A condenser .26 is provided for condensing the exhaust from theejectors, both the expended motive fluid and the compressed vaporwithdrawn from the evaporator. The condenser may be of any suitabletype, for example, of the type having water cooled tubes arranged in aplurality of passes, which type is well known in the art. It comprises ashell 21 having a partition 28 dividing the same into first and secondchambers 29 and 30, respectively. The tubes are arranged so that thecirculating fluid rst passes through tubes in the chamber 29 and thenthrough tubes in the chamber 30. For example, the irst two passes may bein the chamber 29 and four more passes may be arranged in the chamber30. As the cooling iiuid passes first through the chamber 29, itmaintains a lower pressure therein than in the chamber 30. In accordancewith the present invention, the outlets of the low pressure ejectors .I3connected through conduits 3| to the low pressure chamber 29, and thehigh pressure ejectors I9 are connected through conduits-321m the higherpressure chamber 30.

Suitable air removal apparatus is provided, for example, an ejector 3|'removes air and noncondensible vapor from the chamber 29 and exhauststhe same into a higher pressure chamber 30, and another ejector 32',which may comprise aplurallty of stages, is connected to the chamber 30for removing air and uncondensed vapor therefrom. The suction inlets ofthe ejectors 3|' and 32' are connected to the chambers at suitablepoints, preferably remote from the inlets through which the exhaust fromthe ejectors is admitted.

Suitable provision forsupplying motive uid to' this ejector, is, ofcourse, provided. Suitable provision is made for removing condensatefrom the chambers 29 and 30, as is well understood in the art.

Automatic control mechanism may be provided for varying the number ofejectors in operation. In Fig. 2, there is shown such an automaticcontrol mechanism for the two low pressure ejectors I3 and for two ofthe high pressure ejectors I9, the remaining high pressure ejectorsbeing manually controlled. The control mechanism comprises solenoids 33and 34 for actuating the steam admission valves I6 of the low pressureejectors I3 and solenoids 35 and 3S for operating the steam admissionvalves 23 of two of the high pressure ejectors I9. The solenoids 33 to3S are connected to contacts 33a to 33a respectively. The latter areadapted to be successively engaged by the bridging members 3'I of athermostatic switch device 38. The latter comprises a bellows 39 foractuating said bridging members 37, a thermostatic bulb Il!) disposed inthe chilled water outlet connection I2, containing an expansible uid,and a tube 4I connecting said bulb and bellows.

Operation The operation will rst be described assuming all ejectors tobe operating. Low pressure steam is supplied to the low pressureejectors I3 and high pressure steam is supplied to the high pressureejectors I9. Water to be cooled is circulated through the evaporator inany suitable known manner, being admitted through the inlet connectionsII and withdrawn through the outlet connection I2. 'Ihe ejectorswithdraw vapor from the evaporator, thereby reducing the pressuretherein. Such pressure reduction effects vaporization of a portion ofthe water with consequent cooling of the remaining portion. The vaporwithdrawn from the vaporator, together with the expanded motive fluid,is discharged by the ejectors into the condenser 2S, the low pressureejectors I3 discharging into the chamber 29 and the high pressureejectors I9 discharging into the chamber 30. y

The condenser is cooled by means of a supply of cold Water which iscirculated, in any suitable known manner, rst through the first andsecond tube passes in the chamber 29 and then through the third to thesixthv tube passes in the chamber 30. Inasmuch as the water in the tubesin the chamber 39 has absorbed heat from the chamber 29, its temperatureis higher than that of the water in the tubes in the chamber 29.Accordingly, a higher vacuum, or lower absolute pressure is maintainedin the chamber 29 than in the chamber 30. The provision of 'the bestvacuum for the low pressure ejectors I3 provides the maximum heat dropor pressure drop of the low pressure steam supplied toI said ejectorsfor motivating the'steam. 'Ihe ejectors I9 are provided with higherpressure steam, which is better able to exhaust against the higherabsolute pressure in the chamber 30.

During a great portion of the operation of the apparatus, only a limitednumber of ejectors need be operated. Inasmuch as the low pressure steamis usually steam that is otherwise Wasted, the low pressure ejectors I3are rst placed in operation and then, as greater cooling action isrequired, the high pressure ejectors I9 are brought into operation. Thismay be done manually or, when automatic control is provided as in theillustrated embodiment, it is automatically eiected in the followingmanner: I

When the temperature of the water flowing through the outlet connectionI2 is so low as to indicate that no cooling is required, the bridgingmembers 3l of the thermostatic switch device 38 are moved to the rightto disengage all of the contacts. Accordingly, all of the solenoids aredeenergized and the steam admission valves are closed. As the coolingload increases, indicated by rise :in temperature of the water flowingthrough the outlet connect-ion I2, the fluid in the thermostatic bulbIII) expands, causing the bellows 39 to move the bridging members 31 tothe left. The latter are arranged relative to the contacts 33a to 36a,as will be readily seen from Fig. 2, so as to engage said contacts inthe order name-d. Thus, in response to a light load the solenoid 33 willopen the steam admission valve I6 of the first low pressure ejector I3,and upon further increase, the solenoid 34 will open the steam admissionvalve of the other low pressure ejector I3. When the reirigerating loadincreases beyond the capacity of the two low pressure ejectors, then thesolenoid 35 will open the steam admission'valve of the rst high pressureejector I9 and upon still further increase, the solenoid 36 will openthe steam admission valve of a second high pressure ejector I9. Upondecrease in refrigerating load, the ejectors are closed in reverseorder.

The remaining high pressure ejectors I9 are provided with manuallyoperated steam admission Valves 23, and may be used to carry base load,the automatically controlled ejectors pro- Viding for the Variations incooling load in a manner well known in the art.

It will thus be seen that the low pressure steam is first used as far aspossible and that the high pressure steam is used only when necessary.During a large portion of the operating period, the refrigerating loadwill be suiciently low so that the same is carried mainly or entirely bylow pressure steam.

It will also be noted that the best vacuum is provided for the lowpressure ejectors which are operated the greatest portion of the timeand which utilize steam that would otherwise be wasted. f'

In Fig. 3, I show my invention applied to apparatus in which cooling ofthe water or other liquid to be cooled is effected in a plurality ofstages, the evaporator I0 being divided into chambers 42 and 43. Thewater to be cooled is admitted through a conduit II and admitted intothe chamber 42 through a pipe l having spray openings l5 therein. Thewater collects in the bottom of the chamber 42 and flows by gravitythrough a conduit 46, formed to provide a loop seal, into an annularpipe 'I in the cham ber 43, which con-duit has spray openings t8therein. From the chamber 43, the cooled water is withdrawn through anoutlet connection 49.

An ejector I9', designed and constructed for operation with highpressure motive iluid has its suction inlet connected to the chamber d2.An ejector I3', designed and constructed to operate with motive fluid oflower pressure has its suction inlet connected to the chamber 43. Bales5U may be provided in the chambers 42 and 43 adjacent the connectionswith ejectors, to minimize entrainment of solid particles of water.

The low pressure ejector I3 and the high pres- CII sure ejector I9'discharge into chambers 29' and 30 of a condenser 26. This condenser isalso arranged so that cooling fluid flows rst through the chamber 29 andthen through the chamber'30', thereby maintaining a higher vacuum in thechamber 29.

In the operation of this embodiment, a portion of the cooling of theWater is eiected in the chamber 42, the vapor being withdrawn therefromby the high' pressure ejector I9'. The remaining portion of the coolingis effected in the chamber 43, the vapor being withdrawn with the lowpressure ejector I3'. Inasmuch as the temperature of the water is lowerin the chamber 43, a lower pressure, or higher vacuum, is maintainedtherein.

At partial load, the high pressure ejector I9' may be shut down and onlythe low pressure ejector I3 operated. This may be eiected by automaticcontrol mechanism similar to that shown in Fig. 2 and includingsolenoids 5I and 52 controlling the motive steam supply to the ejectorsI3' and I9', respectively, and in turn controlled by contacts 53 and 54,respectively. A thermostat switch device 38, similar to that shown inFig. 2, engages the contact 53 to effect operation of the low pressureejector I3', only upon light load, and engages both contacts to effectoperlets of the ejectors are opened in any suitablev manner at suchtimes as the'ejecting action of the associated ejectors is established.Also, the ejectors may embody starting nozzles, in which case suitableknown forms of control therefor may `-be employed. It will also beapparent that the number of iowpressure ejectors and the number of highpressure ejectors will be such as are most suitable for the particularconditions encountered in each installation.

While' I have shown my invention in several forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modifications Without departing from thespirit thereof, and I desire, therefore, that only such limitationsshall be placed thereupon as are imposed by the prior art or as arespecifically set forth in the appended claims.

What I claim is:

1. In vapor jet refrigerating apparatus, the combination of evaporatormeans, rst and second `ejectors for withdrawing vapor from saidevaporating means to eifect cooling by evaporation of liquid therein,said first and said second ejector being designed and constructed foroperation with motive iiuid of relatively low pressure and motive fluidof relatively high pressure, respectively, condensing means comprisingfirst and second condensing chambers for condensing the "respectively,and means for conveying cooling gapor exhausted by said first and secondejectors,

water through said iirst and second condensingI chambers in series inthe order named, whereby the first ejector utilizing motive fluid of lowpressure exhausts into a region of lower pressure than the secondejector.

2. InV vapor jet refrigerating apparatus, the combination of evaporatormeans, rst and second ejectors for withdrawing vapor from saidevaporator means, said first and said second ejector being designed andconstructed for operation with motive fluid of relatively low pressureand motive iiuid of relatively high pressure, respectively, means forsupplying motive vapor of relatively low pressure and motive iiuid ofrelatively high pressure to said first and second ejectors,respectively, means providing first and second condensing chambersconnected to said rst and second ejectors, respectively, and means forcirculating cooling uid in heat exchange relation with said first andsecond condensing chambers in'seriesin the order named and formaintaining a lowerpiessure in said rst chamber than in the secondchamber, whereby the first ejector utilizing motive iiuid of lowpressure exhausts into a region of lower pressure.

3. In vapor jet refrigerating apparatus, the

combination of evaporator means, rst and sec-- ond ejectors forwithdrawing vapor -from said k evaporator means, `saidiirst and saidsecond ejector being designed and constructed for operation with motivefluid of relatively low pressure and motive fluid of relatively highpressure, respectively, means for supplying motive vapor of relativelylow pressure and motive iiuid of relatively high pressure to said firstand second ejectors, respectively,'means providing rst and secondcondensing chambers connected t6 said Aiirst and second ejectors,respectively, means for conveying cooling uid in heat exchange relationwith said first and second chambers in series in the order named,whereby a lower pressure is maintained in said iirst chamber connectedto said first ejector utilizing motive iiuid of low pressure, and meansfor rendering said iirst and second ejectors operative successively inresponse to successive vincreases in refrigerating load, respectively.

4. In vapor jet refrigerating apparatus, the combination of evaporatormeans, rst `and second ejectors for withdrawing vapor from saidevaporatormeans, said first and said second ejector being designed andconstructed for operation with motive iiuidof relatively low pressureand motive uid of relatively high pressure, respectively, means forsupplying motive vapor of relatively loW pressure and motive iiuid ofrelatively high pressure to said iirst and second ejectors,respectively, means providing first and second condensing chambersconnected to said first and second ejectors, respectively, means forconveying cooling fluid in heat exchange relation with said rst andsecond chambers in series in the order named, whereby a lower pressureismaintained in said rst chamber connected to said first ejector utilizingmotive iiuid of low pressure,

-designed and constructed for operation with motive uid of relativelyhigh pressure for withdrawing vapor from said first evaporator chambei',condensing means comprising iirst and secing by evaporation of liquidtherein, discharging the exhaust uid from said rst and second ejectorsinto first and second condensing chambers, respectively, and conveyingcooling uid into heat exchange relation first with the exhaust uid insaid rst condensing chamber and then into heat exchange relation withthe exhaust uid in said second condensing chamber, whereby said rstejectorV utilizing low pressure motive fluid exhausts into a region oflower pressure in the rst 10l condensing chamber.

ERNEST F. STALCUP.

